LinSSS: linear decomposition of heterogeneous subsurface scattering for real-time screen-space rendering
LinSSS: linear decomposition of heterogeneous subsurface scattering for real-time screen-space rendering
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LinSSS：用于实时屏幕空间渲染的异构次表面散射的线性分解
DOI：
10.1007/s00371-020-01915-4
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Morishima Shigeo
中科院分区：
文献类型：
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作者：
Yatagawa Tatsuya;Yamaguchi Yasushi;Morishima Shigeo
屏幕空间次表面散射是目前在实时渲染中表示半透明材料的最常用方法。然而，目前大多数的方法近似的半透明材料的漫反射曲线作为一个对称的函数，而该轮廓具有不对称的形状在性质上。为了解决这个问题，我们提出了LinSSS，一个数值表示的异质次表面散射实时屏幕空间渲染。虽然我们的表示是建立在以前的方法，它有两个贡献。首先，LinSSS将漫反射率轮廓公式化为径向对称高斯函数的线性组合。然而，它也可以代表的空间变化和径向不对称的轮廓。其次，由于LinSSS仅使用高斯函数来公式化，因此可以在屏幕空间中有效地计算漫反射分布的卷积。为了进一步提高效率，我们变形的渲染方程使用LinSSS通过因式分解常见的卷积项和近似的卷积过程中使用MIP映射。因此，我们的方法的工作速度与最先进的方法一样快，而我们的方法成功地代表了散射的异质性。
Screen-space subsurface scattering is currently the most common approach to represent translucent materials in real-time rendering. However, most of the current approaches approximate the diffuse reflectance profile of translucent materials as a symmetric function, whereas the profile has an asymmetric shape in nature. To address this problem, we propose LinSSS, a numerical representation of heterogeneous subsurface scattering for real-time screen-space rendering. Although our representation is built upon a previous method, it makes two contributions. First, LinSSS formulates the diffuse reflectance profile as a linear combination of radially symmetric Gaussian functions. Nevertheless, it can also represent the spatial variation and the radial asymmetry of the profile. Second, since LinSSS is formulated using only the Gaussian functions, the convolution of the diffuse reflectance profile can be efficiently calculated in screen space. To further improve the efficiency, we deform the rendering equation obtained using LinSSS by factoring common convolution terms and approximate the convolution processes using a MIP map. Consequently, our method works as fast as the state-of-the-art method, while our method successfully represents the heterogeneity of scattering.